﻿using System;

namespace Test
{
    class Program
    {
        static void Main(string[] args)
        {//常量的使用
            const double pl = 3.14; int r = 3;
            Console.WriteLine("圆的周长：" + 2 * pl * r);
            Console.WriteLine("圆的面积：" + pl * r * r);

            //命名规则
            string userName = "美女";
            string UserName = "美女";
            Console.WriteLine("我是{0},你也是{1}", userName, UserName);
            //if语句
            Console.WriteLine("请输入您的会员积分");
            int points = int.Parse(Console.ReadLine());
            if (points < 0)
            { points = 0; }
            if (points <= 50)
            { Console.WriteLine("您好,vip用户"); }
            else if (points <= 100)
            { Console.WriteLine("您好,vvip用户"); }
            else
            { Console.WriteLine("您好,vvvip用户"); }
            //switch case
            Console.WriteLine("请输入学生考试成绩（0-100的整数）");
            int poi = int.Parse(Console.ReadLine());
            switch (poi / 10)
            {
                case 10:
                    Console.WriteLine("优秀");
                    break;
                case 9:
                case 8:
                    Console.WriteLine("良好");
                    break;
                case 7:
                case 6:
                    Console.WriteLine("及格");
                    break;
                default:
                    Console.WriteLine("不及格");
                    break;

            }
            Console.ReadLine();
        }
    }
}

